The Importance of Natural Resources Earth’s Land - Chapter 2 The Importance of Natural Resources

Key Concepts natural resources come from the land soil is the most important resource -- plants grow = food source important to conserve soil

Gully! It’s Soil Erosion Geologist – scientists who study Earth materials soil – loose rock material covering the Earth’s land surface soil erodes more quickly from bare soil than with sod plants grown to anchor soil

Soil – A Limited Resource natural resource – any useful material from Earth (ex: coal, trees, air, water, soil) soil most important – plants grow in it (food source for all living things)

Using Soil Wisely greatest cause of soil erosion = running water gullies – miniature river valleys formed conservation – wise use of natural resources To conserve soil: leave plants growing contour plowing – plowing hilly land following shape of land strip cropping – planting cover crop between rows dam building – helps slow or stop formation of gullies terracing – building step-like ridges to prevent or slow down water runoff

Soil Profile topsoil – weathered rock & humus (decayed plant & animal matter – provides nutrients) subsoil – clay particles weathered rock

From Rocks to Riches thinnest layer of Earth – crust (thickest parts are the continents & ocean floors)

An Inside Look at Rocks rock – solid material made up of one or more minerals mineral – natural solid that has a definite chemical makeup, found in Earth’s crust

Uses of Rocks & Minerals rock use depends on its properties - granite – hard rock - marble – beautiful rock - graphite – lead pencils - calcite – chalk - halite - salt

Minerals in Ore ore – rock that can be mined for the minerals it contains metals are most valuable substances that come from ore (ex: iron, copper, gold, aluminum, tin) obtaining metals in ore  long & costly

Resources Worth Saving renewable resource – resource that can be replaced - ex: trees – can plant more nonrenewable resource – resource that cannot be replaced - ex: water, air, - must be conserved or people will need to do without them in the future

Fuels Around the World How does the use of fossil fuels in the United States compare with that of other nations? U.S uses MORE or LESS

Fuel From Living Things Wood – comes from trees / stores energy from sun Solid Animal Waste (dung) – energy stored in plants eaten by animals (CA – power plant)

Fossil Fuels Fossil Fuels – fuels made from the remains of once living things -NONRENEWABLE RESOURCE Ex: natural gas, coal, petroleum (crude oil) Ex: peat – made from remains of ancient swamp plants / can change into coal

Supply & Demand World’s fossil fuels not shared equally. U.S. uses about 47 times more petroleum per person than someone in India. U.S. uses 3 times as much coal as per person in China. Fossil fuels are nonrenewable resources.

They will eventually run out! Coal, Gas, and Black Gold What are the major drawbacks of using fossil fuels as the main source of energy? They will eventually run out!

Energy From Ancient Sunlight All fossil fuels contain energy that was once stored in the cells of living things. Plants & animals got their energy from the SUN.

Fuel From Fossils Millions of years ago plants & animals were covered by mud & sand (ocean floor & swampy areas). Heat & pressure slowly changed the once-living things into petroleum and natural gas. Eventually became peat and can change to coal if given enough time.

Bad News About Fossil Fuels Fossil fuels cannot be replaced in our lifetime. Natural gas & petroleum take millions of years to form. Coal is more plentiful than oil or natural gas. Mining coal destroys huge areas of land, is costly, & takes a long time. Burning fossil fuels adds carbon dioxide and other harmful gases to the air. Carbon dioxide traps & holds heat close to the Earth’s surface = GREENHOUSE EFFECT = CLIMATE CHANGE

Good News About Fossil Fuels It is possible to estimate when supplies will run out. We can remove fossil fuels only as needed. Fossil fuels used to warm rooms, heat water, & power machines.

New Energy Sources solar energy – energy from the Sun wind energy – energy from the wind (windmills) sea water, energy from inside the Earth